1. Field of the Invention
The present invention relates to a speaker system utilizing an adsorption phenomenon of a gas, and equipment accommodating the same.
2. Description of the Related Art
Conventionally, it has been difficult for a small-size speaker system to reproduce a bass sound in consideration of an influence of acoustic stiffness exerted in a chamber of a speaker cabinet. This is because a reproduction limit of the bass sound of the speaker system is determined depending on a capacity of the cabinet. Thus, for the purpose of expanding the reproduction limit of the bass sound without enlarging the capacity of the cabinet, there has been a speaker system which has activated carbon located inside of the cabinet (for example, Patent Document 1).
FIG. 13 is a cross-sectional view of a main portion of the speaker system described in Patent Document 1. Further, FIG. 14 is a cross-sectional view viewed from along line K-L of FIG. 13. In FIG. 13, the speaker system includes a cabinet 101, a woofer 102, activated carbon 103, a supporting material 104, a diaphragm 105, and a vent tube 106. The woofer 102 is fixed to an opening portion of the cabinet 101. The activated carbon 103 is an aggregation of granular activated carbon. A shape of the activated carbon 103 is maintained in a predetermined shape by the supporting material 104. The supporting material 104 is formed by, for example, a netted material, and on a surface thereof, pores are formed so as to allow air to pass through. The diaphragm 105 is located between the woofer 102 and the activated carbon 103, and divides the chamber inside the cabinet 101 into two. The vent tube 106 connects the two chambers divided by the diaphragm 105.
An action of the speaker system shown in FIG. 13 will be described. When an electric signal is applied to the woofer 102, a pressure in a chamber at a side of the woofer 102 changes, and the diaphragm 105 vibrates due to the pressure. Here, with regard to a chamber at the side of the activated carbon 103, a pressure change occurs inside the chamber due to vibration of the diaphragm 105, however, since air molecules inside the chamber are adsorbed by the activated carbon 103 depending on the pressure inside the chamber, the pressure change inside the chamber is suppressed. As a result, the same effect as a case where the capacity of the cabinet 101 is enlarged can be obtained, and consequently, it is possible to reproduce the bass sound even with a small cabinet, as if with a large cabinet.    Patent Document 1: Japanese National Phase PCT Laid-Open Publication No. 60-500645